Culling Chickens and worms

Hi,
We have decided to cull all five of our girls. Though they are not yet two years old, we haven't gotten a good and consistent egg production from them the past three to four months (zero to one egg per day for the last two weeks). It was like that early in the year and we thought it was because of winter. Then, we suspected one of our hens have been eating the eggs. Then, we confirmed it. The problem went away after we bought two fake eggs and stuck it into the nesting box. Unfortunately, somehow or other, the problem returned and all of them are now going after the eggs. I've been watching them closely and I see them attack an egg that was laid in the run voraciously. So we decided to cull. Then, I observed a few days ago that two of them has somewhat soiled feathers around the vent. Isn't that a classic sign of worms? If that is the case, I imagine all of them has it (I wonder if this decreased production and also made them more prone to looking for alternative nutrition). Anyhow, I'm wondering if I should bother with deworming before killing them (so that we can eat them). Is it ok to eat chickens that has worms? Part of me is gross out by that idea. Our new chicks are arriving after Labor Day. We have a few weeks to get the coop ready for them. I don't want the two flocks to meet (for disease control reason as well as to spare the little ones from being terrorized). Any suggestions?

I wouldnt bother worming them since you're going to eat them. Worms, worm larva and worm eggs normally wont be in the edible parts of the chicken. Simply cook your chicken thoroughly as you normally would as with any meat/fish.